Mold clamp device for molding machine and method for controlling air blow timing therefor

Abstract

To provide a mold clamp device for a molding machine that can remove water having entered inside, and a method for controlling an air blow timing thereof.SOLUTION: A mold clamp device for a molding machine of the present invention includes: a clamp body 1; a clamp lever 3 slidably provided within the clamp body 1; and a driving force input structure S for operating the clamp lever 3. The clamp body 1 is attached to a platen P of the molding machine, and the clamp lever 3 detachably fixes a mold M to the platen P. In the mold clamp device K for the molding machine, the clamp body 1 is provided with an air injection part 40 for introducing an air blow into the clamp body 1, and a liquid discharge part 41 for discharging liquid by the air blow is provided below the air injection part 40.SELECTED DRAWING: Figure 8

Description

Technical Field

[0001] The present invention relates to a mold clamping device for a molding machine and an air blow timing control method thereof.

Background Art

[0002] As a clamping device for fixing a clamping object such as a mold, the one described in Japanese Patent Application Laid-Open No. 10-311308 (Patent Document 1) is known. This clamping device is composed of a clamping body, a clamping lever pivotally supported by the clamping body, a driving force input structure for operating the clamping lever, and the like.

[0003] The above clamping device is provided, for example, on a fixed platen and a movable platen of an injection molding machine described in Japanese Patent Application Laid-Open No. 9-66543 (Patent Document 2), and detachably fixes a mold attached to these platens.

[0004] A temperature control fluid is flowed through a mold attached to the injection molding machine by a temperature control fluid supply system.

[0005] During mold replacement work, when releasing the mold fixing of the clamping device and removing the mold from the platen, the fluid (water containing foreign matters such as rust) remaining inside the mold leaks and adheres to the clamping device provided below the platen and enters the inside of the clamping device, causing rust to occur inside the clamping device. Due to the rust and foreign matters contained in the water, the sliding of the internal parts of the clamping device deteriorates, causing malfunction.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0007] In the prior art, in order to prevent rust of the clamp device, it was necessary to wipe off the water hanging on the clamp device when changing the mold, and the maintenance work was very difficult. Also, it was difficult to remove the water that had entered inside.

[0008] Therefore, an object of the present invention is to provide a mold clamping device for an injection molding machine capable of removing water that has entered inside, and an air blowing timing control method therefor.

Means for Solving the Problems

[0009] To achieve the above object, the present invention takes the following means. That is, the mold clamping device for a molding machine of the present invention has a clamp body, a clamp lever slidably provided inside the clamp body, and a driving force input structure for operating the clamp lever. The clamp body is attached to the platen of the molding machine, and the clamp lever is for detachably fixing the mold to the platen. In the mold clamping device for a molding machine, an air injection part for introducing air blowing into the inside of the clamp body is provided in the clamp body, and a liquid discharge part discharged by the air blowing is provided below the air injection part.

[0010] The air injection part preferably has an air injection port, an air ejection port provided at a part facing the clamp lever, and an air passage communicating the air injection port and the air ejection port.

[0011] The liquid discharge part is preferably constituted by a drain hole provided near the joint part between the clamp body and the driving force input structure.

[0012] The air blow timing control method for the machine mold clamp device of the molding machine of the present invention is a method for controlling the timing of air blow that sends air to the air injection part in a molding machine equipped with the machine mold clamp device for the molding machine, and is characterized in that air is blown when exchanging the mold by carrying out the mold from the molding machine.

Effect of the Invention

[0013] According to the present invention, since the air injection part and the liquid discharge part are provided, water and foreign matters that have entered the inside of the mold clamp device for the molding machine are discharged to the outside, and internal rust can be reduced.

Brief Description of the Drawings

[0014]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Embodiments for Carrying Out the Invention

[0015] Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a perspective view of a mold clamping device for an injection molding machine (hereinafter, simply referred to as a “clamping device”). In FIG. 2, a clamping device K is attached to the upper and lower peripheries of a platen P of a side-loading injection molding machine. This clamping device K removably fixes the horizontally inserted mold M to the platen P. From FIG. 3 onwards, the structure of the clamping device K is shown.

[0016] The basic structure of the clamping device K is substantially the same as that shown in Patent Document 1 (Japanese Patent Application Laid-Open No. 10-311308). In the embodiment of the present invention, an air injection part 40 and a liquid discharge part 41 are newly provided.

[0017] First, the basic structure will be described. As shown in FIGS. 3 to 7, the clamping device K includes a clamp body 1, a clamp lever 3 slidably provided in the clamp body 1, and a driving force input structure S (see FIG. 6) for operating the clamp lever 3. The clamp lever 3 is movably supported by the clamp body 1 via a pivot shaft 2. The driving force input structure S includes a wedge member 4 that moves the clamp lever 3 and an actuator 5 that drives the wedge member 4 to move.

[0018] In the following description, the “left-right direction”, “front-rear direction”, and “up-down direction” are defined as the directions in FIG. 4.

[0019] As shown in FIG. 8, the clamp body 1 has a pair of left and right wall members 6, 6 arranged at a predetermined distance in the left-right direction, and a rectangular parallelepiped block member 7 provided at the lower left end between the pair of wall members 6 as shown in FIG. 5. The wall member 6 and the block member 7 are fixed by a pair of bolts 8 (see FIG. 3). Between the pair of left and right wall members 6, the clamp lever 3 and the wedge member 4 are movably disposed. The wedge member 4 is slidably provided in the vertical direction on the vertical surface of the front surface of the block member 7.

[0020] As shown in Fig. 9, a pair of wall members 6 are formed with a pair of long oval holes 9, 9 (lever pivot holes) that are long in the vertical direction facing the opposing space, and these long oval holes 9 are formed to face each other. Both end portions of the pivot shaft 2 of the clamp lever 3 are engaged with and pivotally supported by these long oval holes 9 so as to be movable in the vertical direction. Further, bolt holes 10 are formed in the wall members 6, and the clamp body 1 is fixed around the position where the mold M of the platen P of the injection molding machine is attached by a pair of bolts 11 (see Figs. 4 and 5) inserted through these bolt holes 10 (see Fig. 2).

[0021] As shown in Fig. 5, the clamp lever 3 is pivotally supported by the clamp body 1 via a pivot shaft 2 having an axial center in the left - right direction, has an output portion 12 at its upper end portion, and an input portion 13 at its lower end portion. The output portion 12 protrudes upward from the upper end surface of the clamp body 1 as shown in Fig. 6, and as shown in "Fig. 1" of Patent Document 1, it is a portion for pressing the mold and fixing it to the platen.

[0022] As shown in Figs. 8 to 11, the clamp lever 3 has a left - right width such that both its left and right sides are in sliding contact with the inner surfaces of a pair of wall members 6. The pivot shaft 2 is inserted through the central portion of the clamp lever 3.

[0023] The clamp lever 3 is movable between a clamp - capable position where its output portion 12 protrudes outside the upper end of the clamp body 1 (see Fig. 6) and a retracted position where its output portion 12 retracts into the clamp body 1 in the clamp - released state (see Fig. 5).

[0024] When the clamp lever 3 is in the mold - clamping position, both end portions of the pivot shaft 2 abut against the upper end portions of a pair of long oval holes 9. A driving force is input from the wedge member 4 to the input portion 13, the clamp lever 3 is rotated around the pivot shaft 2, and the mold M is clamped to the platen P by the output portion 12 (see Fig. 2).

[0025] In Fig. 5, a lever portion 14 extending rearward is integrally formed on the clamp lever 3 at the rear side of the pivot shaft 2, and a coil spring 15 is interposed between the lever portion 14 and the block member 7. The lever portion 14 is biased upward by this coil spring 15. Then, due to the biasing force of the coil spring 15, the clamp lever 3 is held at the mold unclamping position. A partial cylindrical surface 16 is formed on the input portion 13, and a shaft member 17 is fitted to this partial cylindrical surface 16. A flat notch surface 18 is formed on the rear surface of the shaft member 17.

[0026] The wedge member 4 is supported on the front surface of the block member 7 so as to be slidable in the vertical direction. The front surface of the wedge member 4 is formed as an inclined surface 19 that is thin at the upper part and thick at the lower part. This inclined surface 19 is in surface contact with the notch surface 18 of the shaft member 17 of the input portion 13 of the clamp lever 3.

[0027] A locking portion 20 is provided at the upper end of the wedge member 4. A locked portion 21 that engages with this locking portion 20 is provided on the input portion 13 of the clamp lever 3. When the wedge member 4 is driven to move downward by the actuator 5, the locked portion 21 of the input portion 13 of the clamp lever 3 is locked by the locking portion 20, and the clamp lever 3 moves downward and switches to the retracted position (the state in Fig. 5). Also, when the wedge member 4 is driven to move upward by the actuator 5, the clamp lever 3 in the retracted position moves forward by the coil spring 15 and switches to the clampable position (see Fig. 6).

[0028] On the front portion of the clamp body 1, a position detection mechanism 22 for detecting the clampable position and the retracted position of the clamp lever 3 is provided (see FIGS. 5 and 7). This position detection mechanism 22 has an engaging portion 24 that engages with a groove portion 23 provided on the front surface of the clamp lever 3, and includes a rod 25 that moves vertically together with the clamp lever 3, a guide member 26 that guides the rod 25 in the vertical direction, a sensor 27 that detects the vertical movement position of the rod 25, and the like. A detection portion 25a for detecting the position of the rod 25 by the sensor 27 is provided on the rod 25. The sensor 27 is electrically connected to a control unit (not shown) by an electric signal line 28 (see FIG. 4). Note that the rod 25, the sensor 27, etc. are covered with a cover member 29.

[0029] In the present embodiment, the actuator 5 is constituted by an air cylinder. Hereinafter, the actuator 5 will be referred to as an air cylinder 5.

[0030] The air cylinder 5 has a cylindrical member 30 arranged with an axis in the vertical direction, an upper lid 31 and a lower lid 32 that cover the upper and lower openings of the cylindrical member 30. It has a piston 33 that is slidably fitted inside the cylindrical member 30 in the vertical direction, and a piston rod 34 that is fixed to the piston 33, penetrates the upper lid 31, extends upward, and has a wedge member 4 fixed to its tip. An upper air operating chamber 35 and a lower air operating chamber 36 partitioned by the piston 33 are formed inside the cylindrical member 30. It has two coil springs 37 and 38 of different sizes installed in the lower air operating chamber 36 to bias the piston 33 upward.

[0031] The air cylinder 5 and the clamp body 1 are integrally coupled by bolts 39 (see FIG. 1) arranged at its four corners.

[0032] When pressurized air at a predetermined pressure is supplied to the upper air operating chamber 35 by an air supply source outside the illustration, the piston 33 and the piston rod 34 are driven to move downward against the biasing forces of the coil springs 37 and 38 (the state shown in FIG. 5). Further, when the pressurized air in the upper air operating chamber 35 is released, the piston 33 and the piston rod 34 move upward by the biasing forces of the coil springs 37 and 38 (the state shown in FIG. 6). Furthermore, when pressurized air is supplied to the lower air operating chamber 36 by the air supply source while the clamp lever 3 is in the clampable position, the wedge member 4 is driven to move upward, and when a driving force is input to the input portion 13 of the clamp lever 3 via the shaft member 17, the clamp lever 3 rotates around the pivot shaft 2, and the output portion 12 clamps the mold.

[0033] In addition, a force multiplying mechanism is constituted by the inclination angle of the inclined surface 19 of the wedge member 4 and the ratio of the lever lengths of the input portion 13 and the output portion 12 with respect to the pivot shaft 2 of the clamp lever 3, and a large clamping force is exerted with a small input.

[0034] When the above clamp device K is attached to the lower part of the platen P of the injection molding machine as shown in FIG. 2, there is a problem that cooling water from the mold M is applied during mold change.

[0035] In the clamp device K having the above basic configuration, during mold change work, when releasing the mold fixing of the clamp device and removing the mold from the platen, the fluid remaining in the mold (water containing foreign matters such as rust) leaks and adheres to the clamp device and enters the inside of the clamp device, causing rust to occur inside the clamp device.

[0036] Therefore, in the embodiment of the present invention, the following configuration is adopted to discharge the water and foreign matters that have entered inside.

[0037] That is, as shown in FIGS. 8 and 9, an air injection portion 40 for introducing an air blow into the inside of the clamp body 1 is provided in the clamp body 1, and a liquid discharge portion 41 to be discharged by the air blow is provided below the air injection portion 40.

[0038] The air injection part 40 is provided on a pair of left and right wall members 6, 6. The air injection part 40 has an air injection port 42, an air ejection port 43 provided at a part facing the clamp lever 3, and an air passage 44 that connects the air injection port 42 and the air ejection port 43.

[0039] The air ejection ports 43 are provided at two locations. One of them faces the side surface of the clamp lever 3 near the pivot shaft 2, and the other is provided so as to face the side surface of the input part 13.

[0040] An air pipe 45 is connected to the air injection port 42. The air pipe 45 is connected to an air blow control unit (not shown). The air blow control unit turns on and off the supply of high-pressure air to the air pipe 45.

[0041] In this embodiment, the air injection port 42 opens on the left and right side surfaces of the wall members 6, 6, but it may be provided on the front surface of the wall members 6, 6 like the air passage 44 shown by the virtual line in FIG. 2.

[0042] As shown in FIGS. 9 to 11, a gap is formed between a pair of left and right wall members 6 and the clamp lever 3. This gap is formed by shaving 1 mm in depth from the left and right side surfaces of the clamp lever, but it is not limited to 1 mm (the hatched part in FIG. 11(a) is the shaved part). This gap can also be formed, for example, by inserting a washer into the pivot shaft 2.

[0043] By forming the gap, it prevents the biting-in of foreign matter and the sticking due to rust. It also promotes the discharge of water and foreign matter by air blowing. In order to prevent the rusting of the clamp lever 3, it may be subjected to surface treatment. As the surface treatment for rust prevention in this case, for example, plating is exemplified. Also, for rust prevention, it may be made corrosion-resistant by changing the material from steel to stainless steel.

[0044] The liquid discharge part 41 is provided near the joint part between the clamp body 1 and the driving force input structure S. Specifically, the liquid discharge part 41 is constituted by a drain hole 46 provided near the joint part between the clamp body 1 and the air cylinder 5 (see FIGS. 3, 8, and 12).

[0045] As shown in FIG. 12, a recess 47 is formed inside the joint part between the lower ends of the pair of left and right wall members 6 and the upper end of the upper lid 31 of the air cylinder 5. A plurality of drain holes 46 are provided in the upper lid 31 so as to communicate the recess 47 with the outside.

[0046] Next, in an injection molding machine equipped with a clamp device, an air blow timing control method for sending air to the air injection part 40 during mold exchange work will be described.

[0047] Although not shown in the figure, a control device for signal exchange is provided between the injection molding machine and the mold exchange device. This control device is also connected to the air blow control unit to turn on and off the supply of high-pressure air to the air pipe 45.

[0048] The air blow timing control method of the present embodiment blows air during mold exchange when the mold M is carried out from the molding machine. A particularly efficient timing is to blow air after the mold is carried out from the injection molding machine.

[0049] That is, the air blow is turned on and started from the timing when the mold comes out of the molding machine, and is turned off and stopped after, for example, 30 seconds by a timer.

[0050] As shown by the arrow in FIG. 8, during mold exchange work, the cooling water accumulated in the mold leaks and enters the inside of the clamp body 1 from the upper opening of the clamp body 1. The entered water and foreign matters travel through the gap between the pair of left and right wall members 6 and the clamp lever 3, and proceed downward as shown by the arrow, and are discharged to the outside through the lower drain hole 46.

[0051] Upon receiving the signal that the mold has been unloaded from the injection molding machine, the air blow control unit turns on the air blow to supply high-pressure air to the air pipe 45.

[0052] As shown by the arrows in FIGS. 9 and 12, the high-pressure air jets out from the air jet outlet 43 into the clamp body 1, discharging the water and foreign matter adhering to the inner surface of the clamp body 1 and the surface of the clamp lever 3 to the outside through the drain hole 46.

[0053] According to the above embodiment, since the air jet outlet 43 is provided at a position facing the clamp lever 3, it is easier to remove the water and foreign matter in the gap. Also, since the drain hole 46 is provided, as shown by the arrow in FIG. 12, the flow of the air blow is improved, making it easier to remove the water and foreign matter. Note that by setting the timing of the start of the air blow after the mold has been unloaded, the consumption of high-pressure air can be suppressed compared to starting earlier, and drainage can be performed efficiently.

[0054] The present invention is not limited to that shown in the embodiments. For example, as the driving force input structure S, the wedge member 4 for moving the clamp lever 3 and the actuator 5 for driving the wedge member 4 to move are exemplified, but it is not limited thereto. Instead of the wedge member 4, a direct cylinder push or an eccentric structure may be used. Although the air cylinder 5 is exemplified, a hydraulic cylinder may also be used. The air jet outlets 43 are exemplified as being provided at two locations on one side, but the number and arrangement positions thereof are not limited. Also, a block may be provided on the front side of the clamp body, and an air jet outlet may be provided in this block to blow air into the clamp body from the front. In short, as long as the ejected air can flow through the "gap" between the wall member 6 and the clamp lever 3 to discharge water and foreign matter. The drain hole may be provided at the lower part of the clamp body. Also, the drain hole is not limited to a round hole, and may be a square hole or a gap formed at the joint between the clamp body and the lid member. Also, the molding machine is not limited to an injection molding machine, and a die-casting machine is also applicable. The case of the "mold vertical loading type" in which the mold clamping device is installed left and right is also applicable.

[0055] The scope of the present invention is defined by the claims, rather than the above description, and includes all modifications within the meaning and scope equivalent to the claims.

Explanation of Reference Numerals

[0056] K clamp device M mold P platen of molding machine S driving force input structure 1 clamp body 2 pivot shaft 3 clamp lever 4 wedge member 5 actuator 6 wall member 7 block member 8 bolt 9 oblong hole 10 bolt hole 11 bolt 12 output part 13 input part 14 lever part 15 coil spring 16 partial cylindrical surface 17 shaft member 18 notch surface 19 inclined surface 20 locking part 21 locked part 22 position detection mechanism 23 groove part 24 engaging part 25 rod 25a detection part 26 guide member 27 sensor 28 electric signal line 29 cover member 30 cylindrical member 31 upper cover 32 lower cover 33 piston 34 piston rod 35 upper air operating chamber 36 lower air operating chamber 37 large coil spring 38 small coil spring 39 bolts 40 Air injection part 41 Liquid discharge part 42 Air injection port 43 Air ejection port 44 Air passage 45 Air pipe 46 Drain hole 47 Depression

Claims

1. A mold clamping device for a molding machine, comprising a clamp body, a clamp lever slidably provided in the clamp body, and a driving force input structure for operating the clamp lever, wherein the clamp body is attached to a platen of the molding machine, and the clamp lever is configured to removably fix a mold to the platen. An air injection portion for introducing an air blow into the interior of the clamp body is provided in the clamp body. A mold clamping device for a molding machine, wherein a liquid discharge portion for discharging liquid by the air blow is provided below the air injection portion.

2. The mold clamping device for a molding machine according to claim 1, wherein the air injection portion includes an air injection port, an air ejection port provided at a portion facing the clamp lever, and an air passage communicating the air injection port and the air ejection port.

3. The mold clamping device for a molding machine according to claim 1 or 2, wherein the liquid discharge portion is constituted by a drain hole provided near a joint portion between the clamp body and the driving force input structure.

4. A method for controlling the timing of an air blow for sending air to the air injection portion in a molding machine equipped with the mold clamping device for a molding machine according to any one of claims 1 to 3, A method for controlling the air blow timing of the mold clamping device for a molding machine that blows air when exchanging the mold carried out from the molding machine.

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